When should antiretroviral therapy be started for HIV infection? Interpreting the evidence from observational studies

Predictors of retention in care in HIV-infected patients in a large hospital cohort in Italy

Retention in care is a key feature of the cascade of continuum of care, playing an important role in achieving therapeutic success and being crucial for reduction of HIV transmission. The aim of this study was to evaluate the rate of retention in care in a large referral centre in the North of Italy and to identify predictors associated with failed retention. All new HIV-infected subjects were consecutive enrolled from 1 January 2008 to 31 December 2014. Demographics, immune-virological status, hepatitis co-infection and timing of initiation of combined antiretroviral therapy (cART) data were collected at baseline and at the time of last observation. Failed retention in care was defined as lack of laboratory data, clinical visits and drug dispensation for more than 6 months from the last visit. Cox regression analysis was used. Multivariate analysis of variables with P<0.05 in univariate analysis was performed. We enrolled 269 patients (mean age 46.1 years). Males were 197 (73%), Italian 219 (81%) with mean length of disease of 5.1 years. cART was prescribed for 257 patients (95%). The rate of retention in care was 78.4% and the rate of virological suppression was 75%. Predictors of being loss to follow-up were foreign origin (P = 0.048), CD4+ count <200/mmc (P = 0.001) and not being treated for HIV infection (P = 0.0004). Predictors of cART efficacy were shorter duration of HIV infection and baseline HIV-RNA <100 000 copies/ml. These findings underline the necessity to improve retention in care by identifying groups at increased risk of being loss to follow-up. Retention in care of vulnerable population is crucial to reach 90-90-90 UNAIDS endpoint.

Early HIV Diagnosis Leads to Significantly Decreased Costs in the First 2 Years of HIV Care in an Urban Charity Hospital in New Orleans

We undertook a retrospective cohort study of patients with a positive HIV test in the emergency department who were then linked to care. Inpatient, outpatient, and emergency costs were collected for the first 2 years after HIV diagnosis. Fifty-six patients met the inclusion criteria; they were predominantly uninsured (73%) and African American (89%). The median total cost for a newly diagnosed patient over the first 2 years was US$36 808, driven predominantly by outpatient costs of US$17 512. Median inpatient and total costs were significantly different between the lowest (<200 cells/mm³) and highest (>499 cells/mm³) CD4 count categories (US$21 878 vs US$6607, P <.05; US$61 378 vs US$18 837, P <.05, respectively). Total costs were significantly different between viral load categories <100 000 HIV-RNA copies/mL and ≥100 000 HIV-RNA copies/mL (US$28 219 vs US$49 482, P <.05). Costs were significantly lower among patients diagnosed earlier in their disease. Decreased cost is another factor supporting early diagnosis and linkage to care for patients with HIV.

Factors Associated With Retention Among Non-Perinatally HIV-Infected Youth in the HIV Research Network

BACKGROUND

The transmission of human immunodeficiency virus (HIV) among youth through high-risk behaviors continues to increase. Retention in Care is associated with positive clinical outcomes and a decrease in HIV transmission risk behaviors. We evaluated the clinical and demographic characteristics of non-perinatally HIV (nPHIV)-infected youth associated with retention 1 year after initiating care and in the 2 years thereafter. We also assessed the impact retention in year 1 had on retention in years 2 and 3.

METHODS

This was a retrospective analysis of treatment-naive nPHIV-infected 12- to 24-year-old youth presenting for care in 16 US HIV clinical sites within the HIV Research Network between 2002 and 2008. Multivariate logistic regression identified factors associated with retention.

RESULTS

Of 1160 nPHIV-infected youth, 44.6% were retained in care during the first year, and 22.4% were retained in all 3 years. Retention in the first year was associated with starting antiretroviral therapy in the first year (adjusted odds ratio [AOR], 3.47 [95% confidence interval (CI), 2.57-4.67]), Hispanic ethnicity (AOR, 1.66 [95% CI, 1.08-2.56]), men who have sex with men (AOR, 1.59 [95% CI, 1.07-2.36]), and receiving care at a pediatric site (AOR, 5.37 [95% CI, 3.20-9.01]). Retention in years 2 and 3 was associated with being retained 1 year after initiating care (AOR, 7.44 [95% CI, 5.11-10.83]).

CONCLUSION

A high proportion of newly enrolled nPHIV-infected youth were not retained for 1 year, and only 1 in 4 were retained for 3 years. Patients who were Hispanic, were men who have sex with men, or were seen at pediatric clinics were more likely to be retained in care. Interventions that target those at risk of being lost to follow up are essential for this high-risk population.

Clinical course and quality of care in ART-naïve patients newly presenting in a HIV outpatient clinic

OBJECTIVES

Little data exist about the quality of care for HIV-infected subjects in Germany. We investigated the clinical course of HIV-infected subjects newly presenting in our HIV outpatient clinic.

METHODS

Antiretroviral therapy (ART)-naïve HIV-infected subjects presenting between 2007 and 2008 were followed until June 2012. Clinical data and laboratory parameters were collected prospectively and analysed retrospectively.

RESULTS

From 281 subjects included, 34 patients (12%) were lost to follow-up. 247 subjects remained, and 171 patients were followed for 1,497 days [1,121/1,726] (all data: median [interquartile range]). ART was started in 199 patients (81%) 182 days [44/849] after HIV diagnosis, and all patients were treated according to European guidelines or within clinical trials. The CD4 cell count at first presentation was 320/µL [160/500] and declined to 210/µL [100/300] at ART start. 12 months thereafter, the CD4 cell count increased to 410/µL [230/545]. The HIV RNA was suppressed below 50 copies/mL after 108 days [63/173] in 182 patients (91%). Initial ART was changed in 71 patients (36%) after 281 days [99/718], in five patients (7%) due to virological failure, in 66 patients (93%) due to other reasons, e.g. side effects or patient's request.

CONCLUSION

Two-thirds of the included patients were followed for more than 3 years, and ART was initiated in 81% of the patients leading to complete virological suppression in most patients. Compliance of physicians with treatment guidelines was high. Late presentation with a severely compromised immune function remains a problem and impairs the otherwise good prognosis of HIV infection.

Auditing national HIV guidelines and policies: The United Kingdom CD4 Surveillance Scheme

The United Kingdom’s CD4 surveillance scheme monitors CD4 cell counts among HIV patients and is a national resource for HIV surveillance. It has driven public health policy and allowed auditing of national HIV testing, treatment and care guidelines.

We demonstrate its utility through four example outputs: median CD4 count at HIV diagnosis; late HIV diagnosis and short-term mortality; the timing of first CD4 count to indicate entry into HIV care; and the proportion of patients with CD4 counts <350 cells/mm3 receiving anti-retroviral therapy (ARV).

In 2009, 95% (61,502/64,420) of adults living with diagnosed HIV infection had CD4 counts available. The median CD4 count at diagnosis increased from 276 to 335 cells/mm3 between 2000 and 2009, indicating modest improvements in HIV testing. In 2009, 52% of patients were diagnosed at a late stage of HIV infection (CD4 <350 cells/mm³); these individuals had a ten-fold risk of dying within a year of their diagnosis compared to those diagnosed promptly. In 2008, the national target of performing a CD4 count within 14 days of diagnosis was met for 61% of patients. National treatment guidelines have largely been met with 83% patients with CD4 <350 cells/mm³ receiving ARV.

The monitoring of CD4 counts is critical to HIV surveillance in the United Kingdom enabling the close monitoring of efforts to reduce morbidity and mortality associated with late diagnosis and underpins the auditing of policies and guidelines. These routine surveillance outputs can be generated at national and local levels to drive and monitor public health policy and prevention efforts.

Using mechanistic models to simulate comparative effectiveness trials of therapy and to estimate long-term outcomes in HIV care

BACKGROUND

In HIV care, it is difficult to decide when to initiate therapy, which drugs to use for initial treatment, and which drugs to use if drug resistance develops. With hundreds of possible drug regimens available and variable patterns of drug resistance, randomized controlled trials cannot answer all HIV treatment decisions. Mechanistic models of HIV infection can be used to conduct virtual therapeutic trials with the goal of predicting outcomes, some of which are long-term and may not fall within the time frame of a typical therapeutic trial.

METHODS

We used a previously developed and validated model of HIV infection to replicate 2 arms of an HIV initial treatment trial (ACTG A5142) and predict long-term outcomes. The model incorporated data about biologic processes involved in the development of drug resistance.

RESULTS

The model reproduced the proportion that developed AIDS (0.04 and 0.05 for the efavirenz arm and lopinavir arms, respectively, vs. 0.04 and 0.06 for the trial), the development of virologic failure (0.27 and 0.33 for the Efavirenz arm and lopinavir arms, respectively, vs. 0.24 and 0.37 for the trial), and drug resistance. The hazard ratio for the time to treatment failure, a combination of resistance and other causes (0.96 for the model vs. 0.75 for the trial; 95% confidence interval, 0.57-0.98), and changes in CD4 cell count, were less accurate. The model estimated longer-term life expectancy, quality-adjusted life expectancy, and HIV-related deaths.

CONCLUSIONS

Mechanistic models of HIV infections have the potential to be useful in comparative effectiveness research.

When to start antiretroviral therapy

The question of when to start combination antiretroviral therapy for treatment-naïve patients has always been controversial. This is particularly true in the current era, with major guidelines recommending very different treatment strategies. Despite a lack of clarity regarding the optimal time to begin therapy, there has been a recent shift toward earlier initiation. This more aggressive approach is driven by several observations. First, effective viral suppression with therapy can prevent non-AIDS-related morbidity and mortality. Second, therapy can prevent irreversible harm to the human immune system. Third, therapy may prevent transmission of HIV to others, and thus have a potential public health benefit. For patients who are motivated and willing to initiate early treatment, the collective benefits of early therapy may outweigh the well-documented risks of antiretroviral medications.

The impact of disease stage on direct medical costs of HIV management: a review of the international literature

The global prevalence of HIV infection continues to grow, as a result of increasing incidence in some countries and improved survival where highly active antiretroviral therapy (HAART) is available. Growing healthcare expenditure and shifts in the types of medical resources used have created a greater need for accurate information on the costs of treatment. The objectives of this review were to compare published estimates of direct medical costs for treating HIV and to determine the impact of disease stage on such costs, based on CD4 cell count and plasma viral load. A literature review was conducted to identify studies meeting prespecified criteria for information content, including an original estimate of the direct medical costs of treating an HIV-infected individual, stratified based on markers of disease progression. Three unpublished cost-of-care studies were also included, which were applied in the economic analyses published in this supplement. A two-step procedure was used to convert costs into a common price year (2004) using country-specific health expenditure inflators and, to account for differences in currency, using health-specific purchasing power parities to express all cost estimates in US dollars. In all nine studies meeting the eligibility criteria, infected individuals were followed longitudinally and a 'bottom-up' approach was used to estimate costs. The same patterns were observed in all studies: the lowest CD4 categories had the highest cost; there was a sharp decrease in costs as CD4 cell counts rose towards 100 cells/mm³; and there was a more gradual decline in costs as CD4 cell counts rose above 100 cells/mm³. In the single study reporting cost according to viral load, it was shown that higher plasma viral load level (> 100,000 HIV-RNA copies/mL) was associated with higher costs of care. The results demonstrate that the cost of treating HIV disease increases with disease progression, particularly at CD4 cell counts below 100 cells/mm³. The suggestion that costs increase as the plasma viral load rises needs independent verification. This review of the literature further suggests that publicly available information on the cost of HAART by disease stage is inadequate. To address the information gap, multiple stakeholders (governments, pharmaceutical industry, private insurers and non-governmental organizations) have begun to establish and support an independent, high quality and standardized multicountry data collection for evaluating the cost of HIV management. An accurate, representative and relevant cost-estimate data resource would provide a valuable asset to healthcare planners that may lead to improved policy and decision-making in managing the HIV epidemic.

Effect of early versus deferred antiretroviral therapy for HIV on survival

BACKGROUND

The optimal time for the initiation of antiretroviral therapy for asymptomatic patients with human immunodeficiency virus (HIV) infection is uncertain.

METHODS

We conducted two parallel analyses involving a total of 17,517 asymptomatic patients with HIV infection in the United States and Canada who received medical care during the period from 1996 through 2005. None of the patients had undergone previous antiretroviral therapy. In each group, we stratified the patients according to the CD4+ count (351 to 500 cells per cubic millimeter or >500 cells per cubic millimeter) at the initiation of antiretroviral therapy. In each group, we compared the relative risk of death for patients who initiated therapy when the CD4+ count was above each of the two thresholds of interest (early-therapy group) with that of patients who deferred therapy until the CD4+ count fell below these thresholds (deferred-therapy group).

RESULTS

In the first analysis, which involved 8362 patients, 2084 (25%) initiated therapy at a CD4+ count of 351 to 500 cells per cubic millimeter, and 6278 (75%) deferred therapy. After adjustment for calendar year, cohort of patients, and demographic and clinical characteristics, among patients in the deferred-therapy group there was an increase in the risk of death of 69%, as compared with that in the early-therapy group (relative risk in the deferred-therapy group, 1.69; 95% confidence interval [CI], 1.26 to 2.26; P<0.001). In the second analysis involving 9155 patients, 2220 (24%) initiated therapy at a CD4+ count of more than 500 cells per cubic millimeter and 6935 (76%) deferred therapy. Among patients in the deferred-therapy group, there was an increase in the risk of death of 94% (relative risk, 1.94; 95% CI, 1.37 to 2.79; P<0.001).

CONCLUSIONS

The early initiation of antiretroviral therapy before the CD4+ count fell below two prespecified thresholds significantly improved survival, as compared with deferred therapy.

The therapeutic implications of timely linkage and early retention in HIV care

Following HIV diagnosis, linkage to outpatient treatment, antiretroviral initiation, and longitudinal retention in care represent the foundation for successful treatment. While prior studies have evaluated these processes in isolation, a systematic evaluation of successive steps in the same cohort of patients has not yet been performed. To ensure optimal long-term outcomes, a better understanding of the interplay of these processes is needed. Therefore, a retrospective cohort study of patients initiating outpatient care at the University of Alabama at Birmingham 1917 HIV=AIDS Clinic between January 2000 and December 2005 was undertaken. Multivariable models determined factors associated with: late diagnosis=linkage to care (initial CD4 < 350 cells=mm3), timely antiretroviral initiation, and retention across the first two years of care. Delayed linkage was observed in two-thirds of the overall sample (n = 567) and was associated with older age (odds ratio [OR] = 1.31 per 10 years; 95%confidence interval [CI] = 1.06-1.62) and African American race (OR = 2.45; 95% CI = 1.60-3.74). Attending all clinic visits (hazard ratio [HR] = 6.45; 95% CI = 4.47-9.31) and lower initial CD4 counts led to earlier antiretroviral initiation. Worse retention in the first 2 years was associated with younger age (OR = 0.68 per 10 years;95% CI = 0.56-0.83), higher baseline CD4 count, and substance abuse (OR = 1.78; 95% CI = 1.16-2.73). Interventions to improve timely HIV diagnosis and linkage to care should focus on older patients and African Americans while efforts to improve retention should address younger patients, those with higher baseline CD4 counts, and substance abuse. Missed clinic visits represent an important obstacle to the timely initiation of antiretroviral therapy. These data inform development of interventions to improve linkage and retention in HIV care, an emerging area of growing importance.

HIV-1 coreceptor usage and CXCR4-specific viral load predict clinical disease progression during combination antiretroviral therapy

BACKGROUND

Although combination antiretroviral therapy (cART) dramatically reduces rates of AIDS and death, a minority of patients experience clinical disease progression during treatment.

OBJECTIVE

To investigate whether detection of CXCR4(X4)-specific strains or quantification of X4-specific HIV-1 load predict clinical outcome.

METHODS

From the Swiss HIV Cohort Study, 96 participants who initiated cART yet subsequently progressed to AIDS or death were compared with 84 contemporaneous, treated nonprogressors. A sensitive heteroduplex tracking assay was developed to quantify plasma X4 and CCR5 variants and resolve HIV-1 load into coreceptor-specific components. Measurements were analyzed as cofactors of progression in multivariable Cox models adjusted for concurrent CD4 cell count and total viral load, applying inverse probability weights to adjust for sampling bias.

RESULTS

Patients with X4 variants at baseline displayed reduced CD4 cell responses compared with those without X4 strains (40 versus 82 cells/microl; P = 0.012). The adjusted multivariable hazard ratio (HR) for clinical progression was 4.8 [95% confidence interval (CI) 2.3-10.0] for those demonstrating X4 strains at baseline. The X4-specific HIV-1 load was a similarly independent predictor, with HR values of 3.7 (95% CI, 1.2-11.3) and 5.9 (95% CI, 2.2-15.0) for baseline loads of 2.2-4.3 and > 4.3 log10 copies/ml, respectively, compared with < 2.2 log10 copies/ml.

CONCLUSIONS

HIV-1 coreceptor usage and X4-specific viral loads strongly predicted disease progression during cART, independent of and in addition to CD4 cell count or total viral load. Detection and quantification of X4 strains promise to be clinically useful biomarkers to guide patient management and study HIV-1 pathogenesis.

Influence of alternative thresholds for initiating HIV treatment on quality-adjusted life expectancy: a decision model

BACKGROUND

The optimal threshold for initiating HIV treatment is unclear.

OBJECTIVE

To compare different thresholds for initiating HIV treatment.

DESIGN

A validated computer simulation was used to weigh important harms from earlier initiation of antiretroviral therapy (toxicity, side effects, and resistance accumulation) against important benefits (decreased HIV-related mortality).

DATA SOURCES

Veterans Aging Cohort Study (5742 HIV-infected patients and 11 484 matched uninfected controls) and published reports.

TARGET POPULATION

Individuals with newly diagnosed chronic HIV infection and varying viral loads (10,000, 30,000, 100,000, and 300,000 copies/mL) and ages (30, 40, and 50 years).

TIME HORIZON

Unlimited.

PERSPECTIVE

Societal.

INTERVENTION

Alternative thresholds for initiating antiretroviral therapy (CD4 counts of 200, 350, and 500 cells/mm3).

OUTCOME MEASURES

Life-years and quality-adjusted life-years (QALYs).

RESULTS OF BASE-CASE ANALYSIS

Although the simulation was biased against earlier treatment initiation because it used an upper-bound assumption for therapy-related toxicity, earlier treatment increased life expectancy and QALYs at age 30 years regardless of viral load (life expectancies with CD4 initiation thresholds of 500, 350, and 200 cells/mm3 were 18.2 years, 17.6 years, and 17.2 years, respectively, for a viral load of 10,000 copies/mL and 17.3 years, 15.9 years, and 14.5 years, respectively, for a viral load of 300,000 copies/mL), and increased life expectancies at age 40 years if viral loads were greater than 30 000 copies/mL (life expectancies were 12.5 years, 12.0 years, and 11.4 years, respectively, for a viral load of 300,000 copies/mL).

RESULTS OF SENSITIVITY ANALYSIS

Findings favoring early treatment were generally robust.

LIMITATIONS

Results favoring later treatment may not be valid. The findings may not be generalizable to women.

CONCLUSION

This simulation suggests that earlier initiation of combination antiretroviral therapy is often favored compared with current recommendations.

Antiretroviral Therapy Cohort Collaboration. Importance of baseline prognostic factors with increasing time since initiation of highly active antiretroviral therapy: collaborative analysis of cohorts of HIV-1-infected patients

BACKGROUND

The extent to which the prognosis for AIDS and death of patients initiating highly active antiretroviral therapy (HAART) continues to be affected by their characteristics at the time of initiation (baseline) is unclear.

METHODS

We analyzed data on 20,379 treatment-naive HIV-1-infected adults who started HAART in 1 of 12 cohort studies in Europe and North America (61,798 person-years of follow-up, 1844 AIDS events, and 1005 deaths).

RESULTS

Although baseline CD4 cell count became less prognostic with time, individuals with a baseline CD4 count <25 cells/microL had persistently higher progression rates than individuals with a baseline CD4 count >350 cells/microL (hazard ratio for AIDS = 2.3, 95% confidence interval [CI]: 1.0 to 2.3; mortality hazard ratio = 2.5, 95% CI: 1.2 to 5.5, 4 to 6 years after starting HAART). Rates of AIDS were persistently higher in individuals who had experienced an AIDS event before starting HAART. Individuals with presumed transmission by means of injection drug use experienced substantially higher rates of AIDS and death than other individuals throughout follow-up (AIDS hazard ratio = 1.6, 95% CI: 0.8 to 3.0; mortality hazard ratio = 3.5, 95% CI: 2.2 to 5.5, 4 to 6 years after starting HAART).

CONCLUSIONS

Compared with other patient groups, injection drug users and patients with advanced immunodeficiency at baseline experience substantially increased rates of AIDS and death up to 6 years after starting HAART.

Change over time of mortality predictors after HAART initiation in a Senegalese cohort

BACKGROUND

In 1998, Senegal was among the first sub-Saharan African countries to launch a Highly active anti-retroviral therapy (HAART) access program. Initial studies have demonstrated the feasibility and efficacy of this initiative. Analyses showed a peak of mortality short after starting HAART warranting an investigation of early and late mortality predictors.

METHODS

404 HIV-1-infected Senegalese adult patients were enrolled and data censored as of September 2005. Predictor effects on mortality were first examined over the whole follow-up period (median 46 months) using a Cox model and Shoenfeld residuals. Then, changes of these effects were examined separately over the early and late treatment periods; i.e., less and more than 6-month follow-up.

RESULTS

During the early period, baseline body mass index and baseline total lymphocyte count were significant predictors of mortality (Hazard Ratios 0.82 [0.72-0.93] and 0.80 [0.69-0.92] per 200 cell/mm3, respectively) while baseline viral load was not significantly associated with mortality. During the late period, viro-immunological markers (baseline CD4-cell count and 6-month viral load) had the highest impact. In addition, the viral load at 6-month was a significant predictor (HR = 1.42 [1.20-1.66]).

CONCLUSION

In this cohort, impaired clinical status could explain the high early mortality rate while viro-immunological markers were rather predictors of late mortality.

When to start antiretroviral therapy

The current literature is controversial in providing evidence to determine the optimal time to initiate therapy among patients with HIV. However, there is evidence that initiating early treatment might provide benefits by treating primary HIV infection, preserving normal immune function, suppressing HIV viral replication, deferring clinical progression, and reducing HIV transmission. The biggest challenges in initiating treatment early are issues related with long-term management, including toxicities, adherence, and drug resistance. However, the availability of superior new antiretroviral drugs and simplified regimens, the development of effective treatment strategy, and further improvement of adherence through directly observed treatment are addressing the issues and changing the balance towards earlier treatment.

Establishing CD4 thresholds for highly active antiretroviral therapy initiation in a cohort of HIV-infected adult Chinese in Hong Kong

Studies on the use and outcome of highly active antiretroviral therapy (HAART) in HIV-infected Chinese have been scarce. We evaluated risk of progression to (1) nonaccidental death and (2) new AIDS-defining illness (ADI) or death in 223, 89.9% of 248 HIV-1-infected adult Chinese patients who were first initiated on HAART between 1997 and 2002, and followed through 2003. The study subjects were mostly male (88.3%), aged between 30-49 years (43.9%), and acquired HIV via sexual contact (95.7%). After a median follow-up of 38.6 months, 13 nonaccidental deaths were observed. Overall, 25 patients developed new ADI or died. Using Kaplan-Meier analyses, there was no survival difference of starting HAART at various CD4 strata but a higher risk of progression to new ADI/death in patients with pretreatment CD4 count less than 100 cells per microliter (p = 0.01). On Cox proportional hazards multivariate regression analyses, pretreatment CD4 counts of less than 100 cells per microliter and less than 150 cells per microliter but not higher levels were the cutoffs for increased progression to death (adjusted hazard ratio [HR] = 4.90, 95% confidence interval [CI]: 1.08-22.22) and new ADI/death (adjusted HR = 14.44, 95% CI: 1.95-106.89), respectively. Age 50 years or greater was the only other independent predictor of mortality and new ADI/death after HAART. Further studies are indicated to validate and discern implications of these preliminary findings of a lower CD4 threshold for antiretroviral therapy in a small Chinese HIV cohort.

Influence of gender and HIV transmission group on initial highly active antiretroviral therapy prescription and treatment response

BACKGROUND

The literature contains conflicting findings on the influence of gender and HIV transmission group on the initial prescription of highly active antiretroviral therapy (HAART) and its biological and clinical efficacy.

METHODS

We conducted a cohort study involving 62 French hospitals. We used Cox proportional hazards models to examine whether gender and HIV transmission group influenced the timing of elective HAART initiation, and the clinical and biological response to treatment.

RESULTS

We studied 5735 patients enrolled between January 1997 and December 2001 who did not start HAART or develop a stage C HIV-related event during the first 3 months after inclusion. In multivariate analysis, no gender differences were found in the interval between enrollment in the database and HAART initiation, but this interval was shorter in homosexual patients than in other transmission groups; CD4 cell counts at treatment initiation were also higher in the homosexual group. The immunovirological response to treatment did not differ according to gender, but was better in homosexual patients than in patients in other categories. Injecting drug users had the weakest immunovirological responses. Clinical outcome was not related to gender or to HIV transmission group.

CONCLUSIONS

The interval between diagnosis of HIV-1 infection and elective HAART initiation was not influenced by gender. However, homosexual patients had higher CD4 cell counts than other patients at treatment initiation, and also had better immunovirological responses.

Initiation of antiretroviral therapy

PURPOSE OF REVIEW

Until there is a therapy or a vaccine that can eradicate HIV infection, it is important to continue debating the issues of when and how to use the many antiviral agents licensed as initial treatment since there remain many areas of uncertainty.

RECENT FINDINGS

Early initiation of treatment may be beneficial in terms of HIV progression but it has to be weighed against the risks of adverse drug side effects and complications. In first-line treatment the choice of nucleoside backbones has become limited due to the availability of once a day combined formulations which have excellent short and long-term side-effect profiles. Whether to use protease inhibitors or nonnucleosides as initial agents still awaits definitive data, but again once a day therapy appears to be the preferred option.

SUMMARY

There are only a few initial treatment regimens which are convenient and well tolerated. Starting treatment early will only become a possibility if the agents used cause no long-term problems and no significant resistance. New agents are emerging but it is unlikely that they will manage to reach these exacting standards. There is a need for authoritative adherence research with the results being translated into general care.

To tell or not to tell: why people with HIV share or don't share with their physicians whether they are taking their medications as prescribed

This qualitative study examines whether HIV-positive people (N = 79) tell their physicians whether they take antiretroviral treatment (ART) as prescribed and why. Interviews, analyzed with qualitative content-analysis, asked about taking/not taking ART and, if taking, whether they shared their reasons for non-adherence with their physician. Patients are more likely to inform physicians why they take than why they do not take ART (p<0.01). Only half of those not taking ART shared the reasons for their decision with their physician. The six motives were: anticipation that physicians will not support the decision, cannot discuss feelings, lack of trust in physician's opinion, unable to discuss spiritual/moral issues, no need for physician to know, and not seen physician yet. Of those taking ART, 21% did not tell their physician why they missed doses. The five motives were: not viewed as important, physician not asking, not seen physician yet, rarely non-adherent, no indications in surrogate markers. A significant proportion of patients are not taking their medications as prescribed and are not telling their physicians. To facilitate the chance that patients communicate with their physicians, physicians need to ask no need for and, while giving the patients medical information, create a non-judgmental, respectful atmosphere where patients feel comfortable sharing their personal view.

HIV Paediatric Prognostic Markers Collaborative Study. Predictive value of absolute CD4 cell count for disease progression in untreated HIV-1-infected children

OBJECTIVES

To describe the relationship between absolute CD4 cell count and the short-term risk of disease progression in HIV-1-infected children.

DESIGN

A meta-analysis of individual longitudinal data on HIV-1-infected children enrolled in trials and cohort studies in Europe and the USA.

METHODS

The risks of progression to death and AIDS (or death) within 12 months, in terms of age and the most recent CD4 cell count, were estimated using parametric survival models. The analysis was restricted to measurements before the start of antiretroviral therapy except zidovudine monotherapy. The values of the absolute CD4 cell count and percentage predicting selected levels of disease progression risk were determined from this and previous models.

RESULTS

A total of 566 deaths was observed over 9128 person-years of follow-up, and 992 children progressed to AIDS or death over 7309 person-years of follow-up. In children older than 4 or 5 years, the estimated risk of disease progression increased sharply when the CD4 cell count fell below 200-300 cells/microl. As with other immunological markers, CD4 cell count was less prognostic in younger children. The CD4 cell count values predicting a 12-month risk of death of 2-5% and of AIDS of 5-10% were much more strongly influenced by age than equivalent CD4 cell percentage values.

CONCLUSION

This study suggests it may be appropriate to extend CD4 cell count criteria for initiating antiretroviral therapy in HIV-1-infected adults to children as young as 4 or 5 years. Monitoring by CD4 cell count in younger children is problematical because age is a highly influential variable.

Effectiveness and cost effectiveness of early and late prevention of HIV/AIDS progression with antiretrovirals or antibiotics in Southern African adults

As HIV/AIDS drugs are becoming more widely available in Southern Africa, we compared the effectiveness and cost effectiveness of different treatment options, using a Markov Monte Carlo simulation model based on published estimates of disease progression, treatment effectiveness and health care costs. Cost and outcome values were discounted. Quality of life was considered. Acceptability curves summarized uncertainties. Sensitivity analyses tested assumptions. Results showed that triple antiretroviral therapy (ARV) plus antibiotics would prolong life by 6.7 undiscounted years if provided 'late' (CD4 = 200 cells/microl) and by 9.8 years if provided 'early' (CD4 = 350 cells/microl). The incremental undiscounted costs per year of life gained, compared to no preventive therapy, were $17 for isoniazid plus cotrimoxazole started late, $244 for both antibiotics started early, $2454 for ARV plus antibiotics started late and $2784 for ARV plus both antibiotics started early. The discounted incremental costs per quality adjusted life year (QALY) gained were, respectively, $29 saving, $254, $4937 and $3057. Late ARV plus both antibiotics was the strategy most likely to be cost effective if society was willing to pay more than $2000 per life year gained. Cost-effectiveness estimates were sensitive to discounting and assumed treatment costs but were less sensitive to assumed treatment effectiveness.

Impact of baseline viral load and adherence on survival of HIV-infected adults with baseline CD4 cell counts > or = 200 cells/microl

BACKGROUND

Baseline plasma HIV RNA levels > 100 000 copies/ml have been associated with elevated mortality rates after the initiation of HAART. There is uncertainty regarding the optimal strategy for patients with high plasma HIV RNA but CD4 cell count > or = 200 cells/microl.

OBJECTIVE

To evaluate the impact of baseline plasma HIV RNA on survival among patients with CD4 cell counts > or = 200 cells/microl.

METHODS

Patients were stratified by plasma HIV RNA, CD4 cell count and adherence level. Mortality rates were evaluated using Kaplan-Meier methods and Cox regression.

RESULTS

Among 1166 patients initiating HAART with a CD4 cell count > or = 200 cells/microl, a baseline HIV RNA > or = 100 000 copies/ml was statistically associated with elevated mortality among non-adherent patients (log-rank P = 0.032), but not for adherent patients (log-rank P = 0.690). In a multivariate Cox model comparing patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA < 100 000 copies/ml, the mortality rate was statistically similar among patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA > or = 100 000 copies/ml (relative hazard, 1.21; 95% confidence interval, 0.89-1.65; P = 0.232).

CONCLUSION

HIV RNA > or = 100 000 copies/ml was only associated with mortality among HIV-infected patients initiating HAART with CD4 cell counts > or= 200 cells/microl if the patients were non-adherent.

To take or not to take: decision-making about antiretroviral treatment in people living with HIV/AIDS

Knowledge is limited regarding decision-making about antiretroviral treatment (ART) from the patient's perspective. This substudy of a longitudinal study of psychobiologic aspects of long-term survival, conducted in 2003, compares the rationales of HIV-positive individuals (n = 79) deciding to take or not to take ART. Inclusion criteria were HIV/AIDS symptoms, or CD4 nadir less than 350, or viral load greater than 55,000. Those not meeting any criteria for receiving ART (2/2003 U.S. DHHS treatment guidelines) were excluded. Diagnosis was on average 11 years ago; 36% were female, 42% African American, 28% Latino, 24% white, and 6% other. Qualitative content analysis of semistructured interviews identified 10 criteria for the decision to take or not to take ART: CD4/viral load counts (87%), quality of life (85%), knowledge/ beliefs about resistance (66%), mind-body beliefs (65%), adverse effects of ART (59%), easy-to-take regimen (58%), spirituality/worldview (58%), drug resistance (41%), experience of HIV/AIDS symptoms (39%), and preference for complementary/alternative medicine (17%). Participants choosing not to take ART (27%) preferred complementary/alternative medicine (r = 0.43, p = 0.001)1, perceived a better quality of life without ART (r = 0.32, p < 0.004), and weighted avoidance of adverse effects of ART more heavily (r = 0.24, p < 0.030) than participants taking ART (73%). Demographic characteristics related to taking ART were having a partner (r = 0.31, p < 0.008) and having health insurance (r = 0.26, p< 0.040). Decisions to take or not to take ART depend not only on patient medical characteristics, but also on individual beliefs about ART, complementary/alternative medicine, spirituality, and mind-body connection. HIV-positive individuals declining treatment place more weight on alternative medicine, avoiding adverse effects and perceiving a better quality of life through not taking ART.

Comparing costs and effectiveness of different starting points for highly active antiretroviral therapy in HIV-positive patients. Evidence from the ICONA cohort

We evaluated the costs and effectiveness of starting highly active antiretroviral therapy (HAART) at different points during the course of HIV infection, defined on the basis of CD4 T-lymphocytes counts. The study considered 3,250 HAART-naive patients of the Italian Cohort Naive Antiretrovirals (ICONA), enrolled and followed between 1997 and 2002. In correspondence to the thresholds of 500, 350, and 200 CD4 cells/mm(3), we selected immediate and deferred groups accounting for lead-time bias. The effects of immediate vs. deferred treatment on AIDS-free survival and direct health costs were estimated stratifying on the propensity score of immediate HAART initiation. The incremental cost-effectiveness ratio (ICER) and the cost-effectiveness acceptability curve were also obtained. Although immediate HAART initiation did not affect incidence AIDS and death at high CD4 levels, starting HAART with 200-349 CD4 cells/mm(3) rather than deferring it below 200 CD4 cells/mm(3), proved to be cost-effective.

When to Initiate Highly Active Antiretroviral Therapy in Sub-Saharan Africa? A South African Cost-Effectiveness Study

Background

Large-scale programmes increasing access to highly active antiretroviral therapy (HAART) are being implemented in sub-Saharan Africa. However, cost-effectiveness of initiating treatment at different CD4 count thresholds has not been explored in resource-poor settings.

Methods

A cost-effectiveness analysis was conducted from a public health perspective using primary treatment outcomes, healthcare utilisation and cost data (Jan 2004 local prices; US$1=7.6 Rands) derived from the Cape Town AIDS Cohort. A Markov state-transition model was developed to estimate life-expectancy, lifetime costs, quality-adjusted life-years (QALYs), cost per life-year and QALY gained for initiating HAART at three CD4 cell count thresholds (<200/μl, 200–350/μl and >350/μl), including the no antiretroviral therapy (No-ART) alternative. Each treatment option was compared with the next most effective undominated option.

Results

Mean life-expectancy was 6.2, 18.8, 21.0 and 23.3 years; discounted (8%) QALYs were 3.1, 6.2, 6.7 and 7.4; and discounted lifetime costs were US$5,250, US$5,434, US$5,740, US$6,588 for No-ART, and therapy initiation at <200/μl, 200–350/μl and >350/μl scenarios respectively. Clinical benefits increased significantly with early therapy initiation. Initiating therapy at <200/μl had an incremental cost-effectiveness ratio (ICER) of US$54 per QALY versus No-ART, 200–350/μl had an ICER of US$616 versus therapy initiation at <200/μl, and >350/μl had an ICER of US$1,137 versus therapy initiation at 200–350/μl ICERs were sensitive to HAART cost.

Conclusions

HAART is reasonably cost-effective for HIV-infected patients in South Africa, and most effective if initiated when CD4 count >200/μl. Deferring treatment to <200/μl would reduce the aggregate cost of treatment, but this should be balanced against the significant clinical benefits associated with early therapy.

HIV Paediatric Prognostic Markers Collaborative Study. Use of total lymphocyte count for informing when to start antiretroviral therapy in HIV-infected children: a meta-analysis of longitudinal data

BACKGROUND

Total lymphocyte count has been proposed as an alternative to the percentage of CD4+ T-cells to indicate when antiretroviral therapy should be started in children with HIV in resource-poor settings. We aimed to assess thresholds of total lymphocyte count at which antiretroviral therapy should be considered, and compared monitoring of total lymphocyte count with monitoring of CD4-cell percentage.

METHODS

Longitudinal data on 3917 children with HIV infection were pooled from observational and randomised studies in Europe and the USA. The 12-month risks of death and AIDS by most recent total lymphocyte count and age were estimated by parametric survival models, based on measurements before antiretroviral therapy or during zidovudine monotherapy. Risks were derived and compared at thresholds of total lymphocyte count and CD4-cell percentage for starting antiretroviral therapy recommended in WHO 2003 guidelines.

FINDINGS

Total lymphocyte count was a powerful predictor of the risk of disease progression despite a weak correlation with CD4-cell percentage (r=0.08-0.19 dependent on age). For children older than 2 years, the 12-month risk of death and AIDS increased sharply at values less than 1500-2000 cells per muL, with little trend at higher values. Younger children had higher risks and total lymphocyte count was less prognostic. Mortality risk was substantially higher at thresholds of total lymphocyte count recommended by WHO than at corresponding thresholds of CD4-cell percentage. When the markers were compared at the threshold values at which mortality risks were about equal, total lymphocyte count was as effective as CD4-cell percentage for identifying children before death, but resulted in an earlier start of antiretroviral therapy.

INTERPRETATION

In this population, total lymphocyte count was a strong predictor of short-term disease progression, being only marginally less predictive than CD4-cell percentage. Confirmatory studies in resource-poor settings are needed to identify the most cost-effective markers to guide initiation of antiretroviral therapy.

When to initiate antiretroviral therapy in HIV-1-infected adults: a review for clinicians and patients

One of the most controversial topics in the medical management of HIV disease is the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-1-infected adults. Premature exposure to antiretrovirals may precipitate early evolution of resistance and unnecessary side-effects, whereas remaining off HAART until late in the course of HIV disease may lead to reduced therapeutic benefits and elevated mortality. The lack of a randomised clinical trial to consider this issue has resulted in ongoing revision of expert recommendations and substantial variability between international consensus guidelines regarding the optimal time to initiate therapy. Since this uncertainty is a source of unease for both patients and clinicians, we summarise the latest evidence regarding the optimal time to initiate HAART with consideration of the potential benefits and drawbacks of starting HIV treatment at the different levels presently recommended in leading consensus guidelines.

Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy

BACKGROUND

The costs, benefits, and cost-effectiveness of screening for human immunodeficiency virus (HIV) in health care settings during the era of highly active antiretroviral therapy (HAART) have not been determined.

METHODS

We developed a Markov model of costs, quality of life, and survival associated with an HIV-screening program as compared with current practice. In both strategies, symptomatic patients were identified through symptom-based case finding. Identified patients started treatment when their CD4 count dropped to 350 cells per cubic millimeter. Disease progression was defined on the basis of CD4 levels and viral load. The likelihood of sexual transmission was based on viral load, knowledge of HIV status, and efficacy of counseling.

RESULTS

Given a 1 percent prevalence of unidentified HIV infection, screening increased life expectancy by 5.48 days, or 4.70 quality-adjusted days, at an estimated cost of 194 dollars per screened patient, for a cost-effectiveness ratio of 15,078 dollars per quality-adjusted life-year. Screening cost less than 50,000 dollars per quality-adjusted life-year if the prevalence of unidentified HIV infection exceeded 0.05 percent. Excluding HIV transmission, the cost-effectiveness of screening was 41,736 dollars per quality-adjusted life-year. Screening every five years, as compared with a one-time screening program, cost 57,138 dollars per quality-adjusted life-year, but was more attractive in settings with a high incidence of infection. Our results were sensitive to the efficacy of behavior modification, the benefit of early identification and therapy, and the prevalence and incidence of HIV infection.

CONCLUSIONS

The cost-effectiveness of routine HIV screening in health care settings, even in relatively low-prevalence populations, is similar to that of commonly accepted interventions, and such programs should be expanded.

The case for earlier treatment of HIV infection

Current US guidelines advise that antiretroviral therapy for asymptomatic HIV patients should definitely be started for those who have CD4(+) cell counts of >200 cells/ microL, but antiretroviral therapy is often not started at CD4(+) cell counts much above that level. Guidelines advocating later therapy for HIV infection have been based mainly on sparse and limited cross-sectional data and have been predicated on avoiding drug-related toxicity and viral drug resistance. However, emerging data about factors that contribute to survival and the availability of newer, less toxic drugs are eroding this position. Earlier initiation of antiretroviral therapy--namely, for patients with CD4(+) cell counts of >350 cells/ microL--may, in fact, be associated with lower mortality, better immune improvement, and less drug-related toxicity. These findings coincide with the introduction of antiretroviral drugs that have become more effective and less difficult to take. Earlier initiation of therapy may also reduce HIV transmission, an important public health consideration, and may be beneficial in terms of overall therapeutic cost-effectiveness. Given these accumulating data, we believe reconsideration of the "when-to-start" question is timely and justified.

Response to highly active antiretroviral therapy varies with age: the UK and Ireland Collaborative HIV Paediatric Study

OBJECTIVE

To evaluate the effect of age, CD4 percentage (CD4%) and plasma HIV-1 RNA on response to highly active antiretroviral therapy (HAART) in previously untreated children.

DESIGN

Cohort study.

METHODS

We examined the association between age at HAART initiation, and CD4 and HIV-1 RNA response using logistic and Cox regression, adjusting for sex, route of infection and pre-HAART values.

RESULTS

CD4% increases of > 10% at 6 months were more likely in younger children [odds ratio (OR), 0.84 per year, P < 0.001] and those with lower pre-HAART CD4% (OR, 0.67 per 5% higher, P < 0.001), but were not related to pre-HAART HIV-1 RNA (P = 0.6). In contrast, HIV-1 RNA suppression < 400 copies/ml at 6 months was more likely in older children (OR, 1.09 per year, P = 0.03), and was unrelated to pre-HAART HIV-1 RNA or CD4% (P > 0.3). CD4% was still increasing during the second year following HAART initiation (60% followed > 24 months). Longer-term increases in CD4% occurred faster, and decreases in HIV-1 RNA occurred more slowly in younger children. The median time to CD4% >/= 30% after initiating HAART with CD4% </= 25% was under 12 months for children under 2 years irrespective of pre-HAART CD4%, and increased progressively in older children and as CD4% decreased.

CONCLUSIONS

Children respond immunologically to HAART irrespective of pre-HAART HIV-1 RNA or clinical status. However, immunological response is better in younger children and those with lowest CD4%, whereas younger children have poorer virological response, increasing the risk of resistance. Differences in response to HAART according to age and underlying risk of disease progression should be considered when initiating HAART in children.

PENTA guidelines for the use of antiretroviral therapy, 2004

There have been few major advances in paediatric HIV management over the last 2 years. Decisions about starting antiretroviral therapy can now be based on a recent large meta-analysis of the predictive value of CD4 and HIV RNA viral load (VL) in nearly 4000 untreated children, which is discussed in these updated guidelines. Risk estimates for progression to AIDS and death using surrogate markers can now be broken down by age, allowing more accurate discussion with families. In addition, there is increasing recognition of the problems of long-term adherence, drug resistance and cumulative toxicity in adults and children. The controversy over whether to treat asymptomatic infants continues. For older children more data on the efficacy of ritonavir boosted protease inhibitor (PI) regimens suggests that these may be the PI option of first choice. There is still no adult or paediatric trial evidence on which to base decisions about whether to start with PI- or non-nucleoside reverse transcriptase inhibitor (NNRTI)- based regimens, but the PENPACT 1 trial, which is addressing this question, is ongoing. There are increasing moves to provide simpler antiretroviral therapy (ART) regimens, including once daily dosing, but these lag behind adult regimens because of the paucity of pharmacokinetic data. Resistance assays should now be performed in all HIV-infected infants exposed to ART in pregnancy. Therapeutic drug monitoring may be very important in children because of high between- and within-child variability in drug absorption and metabolism. A trial to evaluate this should start shortly in Europe (PENTA 14 trial). The value of resistance tests for choice of second-line and subsequent choices of ART regimens remain unproven (the PERA trial will report late in 2004), but resistance assays are increasingly being used. The issue of when to switch therapy also remains unanswered and is being addressed within the PENPACT 1 trial. Regular formal assessment of adherence is now the standard of care, and routine monitoring in the clinic for lipodystrophy syndrome (LDS) and other ART toxicities is increasingly important. These guidelines will be updated again in 2006.

Initiating highly active antiretroviral therapy in sub-Saharan Africa: an assessment of the revised World Health Organization scaling-up guidelines

OBJECTIVES

To assess the utility of the 2003 revised World Health Organization (WHO) criteria [initiating highly active antiretroviral therapy (HAART) in stage IV, in stage III plus CD4 cell count < 350 x 10(6) cells/l, or in stage I or II plus CD4 cell count < 200 x 10 cells/l] relative to other scenarios of HAART initiation.

METHODS

Progression to AIDS and death in 292 patients taking HAART and 974 not taking HAART in a South African institution in 1992-2001, stratifying patients by baseline CD4 cell count and WHO stage.

RESULTS

HAART was associated with decreased AIDS [adjusted rate ratio [ARR], 0.16; 95% confidence interval (CI), 0.08-0.31) and death (ARR, 0.10; 95% CI, 0.06-0.18). Benefit of HAART was significant across all WHO stages plus CD4 cell counts. The greatest number of deaths averted was in stages IV [74.0/100 patient-years (PY); 95% CI, 50.2-84.5) and III (32.8/100 PY; 95% CI, 22.4-40.9). AIDS cases averted in stage III (22.0/100 PY; 95% CI, 6.1-26.9) were higher than in stage I and II with CD4 cell count < 200 x 10(6) cells/l (8.9/100 PY 95% CI, 5.6-13.3). Treatment initiation for symptomatic disease resulted in greater benefits than using any CD4 cell thresholds. Application of WHO criteria increased the treatment-eligible proportion from 44.5% to 56.7% (P < 0.05) but did not prevent more death (P > 0.05) than treating symptomatic disease.

CONCLUSION

Implementation of the revised WHO guidelines in sub-Saharan Africa may result in a significantly increased number of individuals eligible for treatment but would not be as effective a strategy for preventing death as treating symptomatic disease.

Can highly active antiretroviral therapy reduce the spread of HIV?: A study in a township of South Africa

BACKGROUND

Calls have been made for the large-scale delivery of highly active antiretroviral therapy (HAART) to people infected with HIV in developing countries. If this is to be done, estimates of the number of people who currently require HAART in high HIV prevalence areas of sub-Saharan Africa are needed, and the impact of the widespread use of HAART on the transmission and, hence, spread of HIV must be assessed.

OBJECTIVES

To estimate the proportion of people eligible for combination antiretroviral therapy and to evaluate the potential impact of providing HAART on the spread of HIV-1 under World Health Organization (WHO) guidelines in a South African township with a high prevalence of HIV-1.

DESIGN

A community-based cross-sectional study in a township near Johannesburg, South Africa, of a random sample of approximately 1000 men and women aged 15 to 49 years.

METHODS

Background characteristics and sexual behavior were recorded by questionnaire. Participants were tested for HIV-1, and their CD4 cell counts and plasma HIV-1 RNA loads were measured. The proportion of people whose CD4 cell count was less than 200 cells/mm and who would be eligible to receive HAART under WHO guidelines was estimated. The potential impact of antiretroviral drugs on the spread of HIV-1 in this setting was determined by estimating among the partnerships engaged in by HIV-1-positive individuals the proportion of spousal and nonspousal partnerships eligible to receive HAART and then by calculating the potential impact of HAART on the annual risk of HIV-1 transmission due to sexual contacts with HIV-1-infected persons. The results were compared with those obtained using United States Department of Health and Human Services (USDHHS) guidelines.

RESULTS

The overall prevalence of HIV-1 infection was 21.8% (19.2%-24.6%), and of these people, 9.5% (6.1%-14.9%) or 2.1% (1.3%-3.3%) of all those aged 15 to 49 years would be eligible for HAART (ranges are 95% confidence limits). In each of the next 3 years 6.3% (4.6%-8.4%) of those currently infected with HIV-1 need to start HAART. Among the partnerships in which individuals were HIV-1-positive, only a small proportion of spousal partnerships (7.6% [3.4%-15.6%]) and nonspousal partnerships (5.7%, [3.0%-10.2%]) involved a partner with a CD4 cell count below 200 cells/mm and would have benefited from the reduction of transmission due to the decrease in plasma HIV-1 RNA load under HAART. Estimates of the impact of HAART on the annual risk of HIV-1 transmission show that this risk would be reduced by 11.9% (7.1%-17.0%). When using USDHHS guidelines, the proportion of HIV-1-positive individuals eligible for HAART reached 56.3% (49.1%-63.2%) and the impact of HAART on the annual risk of HIV-1 transmission reached 71.8% (64.5%-77.5%).

CONCLUSIONS

The population impact of HAART on reducing sexual transmission of HIV-1 is likely to be small under WHO guidelines, and reducing the spread of HIV-1 will depend on further strengthening of conventional prevention efforts. A much higher impact of HAART is to be expected if USDHHS guidelines are used.